02309naa a2200325 a 450000100080000000500110000800800410001910000190006024500530007926000090013250000810014152013000022265000200152265000150154265000230155765300260158065300250160665300300163165300320166165300280169365300230172165300250174470000190176970000180178870000190180670000190182570000260184470000200187077300930189020827712017-12-18       2017    bl uuuu     u00u1 u    #d1 aDEMUNER, L. F.  aAdjustment of growth models in broiler chickens.  c2017  aTítulo em português: Ajuste de modelos de crescimento em frangos de corte.  aThe objective of this work was to investigate adjustments of the Gompertz, Logistic, von Bertalanffy, and Richards growth models, in male and female chickens of the Cobb 500, Ross 308, and Hubbard Flex lines. Initially, 1,800 chickens were randomly housed in 36 pens, with six replicates per lineage and sex, fed ad libitum with feed according to gender, and bred until 56 days of age. Average weekly body weight for each line and sex was used to estimate model parameters using the ordinary least squares, weighted by the inverse variance of the body weight and weighted with a first-order autocorrelated error structure. Weighted models and weighted autocorrelated error models showed different parameter values when compared with the unweighted models, modifying the inflection point of the curve and according to the adjusted coefficient of determination, and the standard deviation of the residue and Akaike information criteria exhibited optimal adjustments. Among the models studied, the Richards and the Gompertz models had the best adjustments in all situations, with more realistic parameter estimates. However, the weighted Richards model, with or without ponderation with the autoregressive first order model AR (1), exhibited the best adjustments in females and males, respectively.  aPoultry science  aAvicultura  aModelo matemático  aAutocorrelated errors  aAutoregressive model  aEstrutura de ponderação  aHomogeneidade da variância  aHomogeneity of variance  aMathematical model  aWeighting structures1 aSUCKEVERIS, D.1 aMUÑOZ, J. A.1 aCAETANO, V. C.1 aLIMA, C. G. de1 aFARIA FILHO, D. E. de1 aFARIA, D. E. de  tPesquisa Agropecuária Brasileira, Brasília, DFgv. 52, n. 12, p. 1241-1252, dez. 2017.